29/09/2017 6:46 PM AEST | Updated 29/09/2017 6:47 PM AEST

Details Emerge Of How Three People Tragically Drowned In Their Homes

The 2015 Dungog floods struck swiftly and were ultimately lethal.

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It may not be well-remembered by most, but the morning of April 21, 2015 will be a day forever etched into the history of the NSW town of Dungog in the state's Hunter Valley.

Caught in a powerful east coast low pressure system, it was only a matter of hours for the country town to jump from experiencing heavy rainfall to flash flooding that ultimately took the lives of three people and swept away four houses.

A report from the New South Wales (NSW) Coroner on Friday has finally revealed the terrifying details of the freak weather event that killed Robin MacDonald, 68, Colin Webb, 79, and Brian Wilson, 72, while they were still in their homes.

Striking swiftly, the floodwaters that hit Dungog were not as widespread as other disasters such as the floods that hit places like NSW's Lismore and Queensland's Rockhampton earlier this year, but they ended just as lethal -- with the report highlighting how the residents became trapped in their own houses as waters from the nearby Myall Creek rapidly rose.

According to the Coroner, MacDonald rang for SES assistance on that morning at around 5am however it wasn't until authorities had come and gone -- while also noticing significant increases in the floodwaters of up to "18 inches" within 15 minutes -- that her body was later found face-down in the front room her of home by Rural Fire Service and Fire and Rescue officers at around 9am.

In the report, it is also noted that the officers who found her noticed that the water line of the rising floodwaters had managed to enter her home and had risen to within "an inch and a half of the ceiling".

In similar circumstances, the report also described how both Webb and Wilson were caught in the rapidly rising waters and, despite the best efforts of each of their neighbours to rescue them, eventually both drowned on the front patios of their homes -- unable to keep up with the strength of the water flow.

Despite there being a local flood plan put in place for the town back in 2011 that relied heavily on the SES response to weather events, the Coroner's statement found that the freak event could have in no way been predicted by authorities, labelling it as an "entirely unpredicted, localised weather anomaly involving an extreme rain event".

The findings also reveal how the peak of the heavy rainfall fell within a 76-minute window between 5am and 6:16am on the morning of April 21 and the significant aftermath of the deluge -- including the three deaths -- occurred between 6:16am and 7am.

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The incredible downfall left most parts of Dungog inundated.

"There is no basis to conclude that [local authorities] should have given an evacuation warning or issued an evacuation order any time before about 6:16am," Deputy State Coroner Theresa O'Sullivan said.

"There was nothing about the rainfall or the behaviour of the weather system [prior to 5am] that provided any basis on which to predict the weather anomaly.

"It had a devastating impact on the entire township of Dungog, a devastating physical impact and an even more devastating impact on the human fabric of Dungog."

In light of the revelations, O'Sullivan also made two recommendations for the country town in order for the local population of just over 2,000 could avoid similar tragedies in the future.

The Coroner called for improvements to the local flood warning system that was put in place six years ago so that earlier notifications can be delivered when needed; and also for a Bureau of Meterology (BoM) official to be out-posted in Dungog on a part-time basis as a consultant for live weather events.

However, O'Sullivan also paid tribute to the efforts of local residents in attempting to do all they could to survive the floodwaters, describing them as "courageous".

"The courageous efforts of the residents of Dungog. Were it not for the conduct of a number of people, it is likely that more lives would have been lost," she said.

"This extraordinary weather event was matched by the extraordinary conduct of the residents of Dungog; in many cases their conduct was nothing short of heroic."